The present invention relates to fiber separation methods and apparatus, and more particularly to a new process for mechanically separating the longer outer bast fibers from the shorter woody innercore fibers of annual herbaceous fiber producing plants.
The long outer bast fibers of annual herbaceous fiber producing plants such as Kenaf and Crotalaria are desirable for a number of uses, including, among other things: use as a packing material; use as a material for the manufacturing of carpet pads and other non-woven pads; use as a product from which high grade paper can be manufactured; use as an absorbing medium for liquids such as water and oil; use in producing rope and cordage products; use in bio-degradable netting products for preventing soil erosion; jute bags; and burlap.
Cleanly separating these useful longer outer bast fibers from the short woody innercore fibers of such plants is necessary in order for such fibers to be used in paper, packing, non-woven pads and cordage materials. The clean outer bast fibers are softer and hemp-like; whereas, the innercore fibers are harder, more rough and woody. Thus, the cleaner the bast fibers, the more readily they may be employed as packing materials, pads, paper products and the like. Once separated, the short woody innercore materials may also be used for such things as a bedding medium for animals, potting mix, or oil absorption materials.
Current methods of processing Kenaf, Crotalaria and other related herbaceous fiber producing plants employ the use of a hollow revolving screened cylinder inside an enclosure for separation. This method leaves an unacceptably high percentage (sometimes as much as 20%) of the short woody innercore fibers in the processed product. Unless the final product is approximately 98% clean of the innercore fibers, it cannot be used in making packing materials, pads, paper products, cordage and the other applications described above. Reintroducing the processed product into the revolving screened cylinder time after time may ultimately achieve a separation of perhaps 90%. However, this is still far below the standard necessary for use in the above products, and the continual re-introduction process is costly and time consuming.